Brighter-fatter effect in near-infrared detectors -- I. Theory of flat auto-correlations

Abstract

Weak gravitational lensing studies aim to measure small distortions in the shapes of distant galaxies, and thus place very tight demands on the understanding of detector-induced systematic effects in astronomical images. The Wide-Field Infrared Survey Telescope (WFIRST) will carry out weak lensing measurements in the near infrared using the new Teledyne H4RG-10 detector arrays, which makes the range of possible detector systematics very different from traditional weak lensing measurements using optical CCDs. One of the non-linear detector effects observed in CCDs is the brighter-fatter effect (BFE), in which charge already accumulated in a pixel alters the electric field geometry and causes new charge to be deflected away from brighter pixels. Here we describe the formalism for measuring the BFE using flat field correlation functions in infrared detector arrays. The auto-correlation of CCD flat fields is often used to measure the BFE, but because the infrared detector arrays are read out with the charge "in place," the flat field correlations are dominated by capacitive cross-talk between neighboring pixels (the inter-pixel capacitance, or IPC). Conversely, if the BFE is present and one does not account for it, it can bias correlation measurements of the IPC and photon transfer measurements of the gain. We show that because the infrared detector arrays can be read out non-destructively, one can compute numerous cross-correlation functions between different time slices of the same flat exposures, and that correlations due to IPC and BFE leave distinct imprints. We generate a suite of simulated flat fields and show that the underlying IPC and BFE parameters can be extracted, even when both are present in the simulation. There are some biases in the BFE coefficients up to 12%, which are likely caused by higher order terms that are dropped from this analysis.

45 pages, 4 figures, 1 table, version accepted by PASP, abstract abridged

References in corpus (9)

• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Characterization and correction of charge-induced pixel shifts in DECam
• Evidence for self-interaction of charge distribution in charge-coupled devices
• Laboratory measurement of the brighter-fatter effect in an H2RG infrared detector
• Exploring the brighter fatter effect with the Hyper Suprime-Cam
• Measuring a Charge-Coupled Device Point Spread Function: Euclid Visible Instrument CCD273-84 PSF Performance
• The shape of the Photon Transfer Curve of CCD sensors
• Point-spread function ramifications and deconvolution of a signal dependent blur kernel due to interpixel capacitive coupling
• Principal Component Analysis of Up-the-ramp Sampled IR Array Data

Cited by in corpus (14)

• Euclid. I. Overview of the Euclid mission
• Euclid. III. The NISP Instrument
• Properties and characteristics of the WFIRST H4RG-10 detectors
• The Brighter-Fatter Effect in the JWST MIRI Si:As IBC detectors I. Observations, impact on science, and modelling
• A Joint Roman Space Telescope and Rubin Observatory Synthetic Wide-Field Imaging Survey
• Probing Intra-Halo Light with Galaxy Stacking in CIBER Images
• Superresolution Reconstruction of Severely Undersampled Point-spread Functions Using Point-source Stacking and Deconvolution
• Brighter-fatter effect in near-infrared detectors -- III. Fourier-domain treatment of flat field correlations and application to WFIRST
• Quantum yield and charge diffusion in the Nancy Grace Roman Space Telescope infrared detectors
• An Algorithm to Mitigate Charge Migration Effects in Data from the Near Infrared Imager and Slitless Spectrograph on the James Webb Space Telescope
• Kinematic Lensing Inference I: Characterizing Shape Noise with Simulated Analyses
• Pixel centroid characterization with laser speckle and application to the Nancy Grace Roman Space Telescope detector arrays
• Spot-Based Measurement of the Brighter-Fatter Effect on a Roman Space Telescope H4RG Detector and Comparison with Flat-Field Data
• Charge diffusion and modulation transfer function in a Nancy Grace Roman Space Telescope detector